Drop old testcase definition

All the definitions are hosted by https://gitlab.apertis.org/tests/apertis-test-cases/

Signed-off-by: Emanuele Aina emanuele.aina@collabora.com

tumbler-thumbnailing.yaml

-metadata:
-  name: tumbler-thumbnailing
-  format: "Lava-Test-Shell Test Definition 1.0"
-  description: "Check that all thumbnailing features of tumbler are
-                working properly (large, small, videos, documents, images)."
-  maintainer: "luis.araujo@collabora.co.uk"
-  scope:
-  - functional
-  devices:
-  - i386
-  environment:
-  - lava-test-shell
-
-run:
-  steps:
-    - common/run-test-in-systemd --timeout=900 --user=user --name=run-test env DEBUG=2 ./run-test.sh
-
-parse:
-  pattern: ^(?P<test_case_id>[a-zA-Z0-9_\-\./]+):\s*(?P<result>pass|fail|skip|unknown)$